Regulation Of Arachidonic Acid Metabolism Research Articles

Coptisine protects against transient focal cerebral ischaemic injury by regulation of arachidonic acid metabolism.

Coptisine (Cop), an alkaloid isolated from Rhizoma Coptidis, has a protective effect against central nervous system diseases such as cerebral ischaemia-reperfusion (IR). Dysregulations in fatty acids metabolism are associated with neuroprotection and neuroinflammation. However, the effect of Cop on fatty acids metabolomics during anti-IR remains unclear. Cerebral IR rats were established by middle cerebral artery occlusion, and the therapeutic effect of Cop was evaluated by 2, 3, 5-triphenytetrazolium chloride staining and neurological deficits scores. By liquid chromatography-tandem mass spectrometry (LC-MS/MS), fatty acids metabolomics analysis in ischaemic hemisphere and serum were investigated. We observed Cop (2mg/kg/qd) was able to reduce cerebral infarct size and ameliorate the neurological function score. Meanwhile decrease in tumour necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) after Cop treatment. Compared with control, down-regulation of cyclopentenone PGs (e.g., PGA2, PGJ2, and 15-deoxy- delta-12,14-PGJ2) was observed in cerebral IR, but upregulation of them when followed by Cop treatment. Similarly, we found the ratios of 14,15-dihydroxyeicosatrienoic acid(14,15-DHET)/arachidonic acid and 11,12-DHET/arachidonic acid was lower in cerebral IR injury relative to control, while their ratios were increased after Cop treatment. Our results indicated that Cop protect against cerebral IR injury, and its mechanism might be closely associated with antiinflammation and the regulation of arachidonic acid metabolism.

Integrating network pharmacology and renal metabonomics to reveal the protective mechanism of resveratrol on gouty nephropathy.

Resveratrol (Res) has been demonstrated to have beneficial effects on gouty nephropathy (GN). However, the mechanisms of Res on GN remain unclear. This study aimed to investigate the mechanisms of Res on GN. In this study, network pharmacology technology was used to predict the Res targets in the prevention and treatment of GN. Renal metabonomics was used to identify differential metabolites in kidney tissue of GN model rats. Finally, molecular docking technology was used to verify the binding ability of Res to key targets. Metabonomics analysis showed that 24 potentially important metabolites were involved in the prevention and treatment of GN with Res. After exposure to Res, metabolite levels normalized. The network pharmacology analysis showed that 24 key targets were involved in the prevention and treatment of GN disease. According to the metabolite-gene network diagram, we identified two core genes, PTGS1 and PTGS2, and found that both were involved in the arachidonic acid metabolism pathway. Molecular docking further verified the affinity of Res binding to PTGS1 and PTGS2. In conclusion, the mechanism of Res against GN may be the regulation of arachidonic acid metabolism through the regulation of PTGS 1 and PTGS 2.

Transcriptomics and metabolomics reveal the regulation of reproductive performance and egg quality of blotched snakehead Channa maculata broodstock induced by a high protein diet

To evaluate the effects of dietary protein on reproductive performance, egg quality and larval health of the blotched snakehead Channa maculata, three groups were designed: a high protein group (HP) with 48% protein content, a low protein group (LP) with 44% protein content, and a control group (C) fed with commercial feed containing 40% protein. The results demonstrated that the HP diet significantly enhanced maternal absolute fecundity, egg size and offspring health; however, it had no impact on fertilization rate and hatching rate. The maternal plasma levels of 11-ketotestosterone, 17β-estradiol, and vitellogenin in the HP group were found to be significantly higher compared to those in the C group. Plasma SOD activity and T-AOC capacity in the HP group were significantly higher than those in the C group, while MDA content showed an opposite trend. The trend of T-AOC in 7 days post-hatching larvae exhibited a consistent pattern with that observed in the maternal. Metabolomics and transcriptomics results indirectly indicated that the differences in reproductive and egg quality of the broodstock were associated with the regulation of arachidonic acid metabolism, steroid hormone biosynthesis, cholesterol metabolism, glycerophospholipid metabolism, and glycerolipid metabolism. The expression levels of star, zp3, foxo3, tgf-β, ghr, igf, cyp17a1, and cyp19a1 genes associated with reproduction and were significantly upregulated in the HP group. By depleting the abundance of metabolites in key pathway such as the pentose phosphate pathway, glycolysis/gluconeogenesis, nicotinate and nicotinamide metabolism, vitamin B6 metabolism within the ovary, there is an elevation in arachidonic acid metabolite abundance, thereby facilitating ovarian maturation and regulating egg quality. In conclusion, the high protein diet may affect the reproductive process and egg quality by inducing an upregulation of TGF-beta signaling pathway and ovarian steroidogenesis and arachidonic acid metabolism, leading to increased plasma cholesterol levels and enhanced steroid hormone synthesis.

Aspirin eugenol ester ameliorates LPS-induced inflammatory responses in RAW264.7 cells and mice.

Introduction: Inflammation is a defensive response of the body and the pathological basis of many diseases. However, excessive inflammation and chronic inflammation impair the homeostasis of the organism. Arachidonic acid (AA) has a close relationship with inflammation and is the main mediator of the pro-inflammatory response. Based on the prodrug principle, the new pharmaceutical compound aspirin eugenol ester (AEE) was designed and synthesized. However, the effects of AEE on key enzymes, metabolites and inflammatory signaling pathways in the AA metabolic network have not been reported. Methods: In this study, the anti-inflammation effects of AEE were first investigated in mice and RAW264.7 cells in LPS induced inflammation model. Then, the changes of the key enzymes and AA metabolites were explored by RT-PCR and targeted metabolomics. Moreover, the regulatory effects on NF-kB and MAPKS signaling pathways were explored by Western Blotting. Results: Results indicated that AEE significantly reduced the number of leukocyte and increased the lymphocyte percentage. AEE decreased the expression levels of IL-1β, IL-6, IL-8 and TNF-α both in vivo and in vitro. In the liver of mice, AEE downregulated the levels of AA, prostaglandin D2 (PGD2) and upregulated 12- hydroxyeicosatetraenoic acid (12-HETE). However, the changes of PGE2, PGF2α, 6-keto-prostaglandin F1α (6-KETO-PGF1α), 9-hydroxy-octadecenoic acid (9- HODE), 13-HODE, 15-HETE, docosahexaenoic acid (DHA) and thromboxane B2 (TXB2) were not significant. Additionally, it was found that AEE decreased the relative mRNA expression levels of p65 and p38 and the ratio of p-p65/p65. Discussion: It was concluded that AEE might inhibit the LPS-induced inflammatory response through the regulation of AA metabolism. This study provides the theoretical foundation for the development of AEE as a medicinal anti-inflammatory drug.

Geniposide improves bleomycin-induced pulmonary fibrosis by inhibiting NLRP3 inflammasome activation and modulating metabolism

Geniposide (Gen) is a natural compound derived from Gardenia jasminoides that has anti-inflammatory, antioxidative stress, antiapoptotic, and antitumour properties. However, its mechanisms of action in idiopathic pulmonary fibrosis (IPF) have not been well studied. Recent studies have found that the progression of IPF is influenced by host metabolism. This study investigated the antifibrotic effects and metabolic modulation of Gen. Gen significantly ameliorated pathological injury in the IPF mouse model. Gen reduced the expression of proinflammatory cytokines and inhibited oxidative stress levels. Gen also inhibited NLRP3 inflammasome activation. Untargeted metabolomics analysis revealed that metabolites were affected in the lung. These metabolites were associated with the regulation of arachidonic acid metabolism, histidine metabolism, and tryptophan metabolism. Gen reduced the inflammatory response and oxidative stress and inhibited NLRP3 inflammasome activation in IPF mice. Mechanistically, Gen-mediated treatment of IPF may be linked to the regulation of host metabolism.

PLA2G12B Mediates Arachidonic Acid Metabolism through Activation of the NF-κB Pathway to Promote Membrane Nephropathy

Introduction: The disruption of podocyte structure and function are the main pathological mechanism of membranous nephropathy (MN). Phospholipases A2, Group XII B (PLA2G12B) was reported involved in the regulation of MN by interfering with arachidonic acid (AA) metabolism, but there is a lack of sufficient evidence. In this study, we investigated the role and molecular mechanism of PLA2G12B in MN. Methods: C57BL/6 mice were used to establish MN model to extract primary podocytes, then divided into control, model, si-phospholipases A2 receptor (PLA2R), PLA2G12B, PLA2G12B + si-PLA2R, PLA2G12B + nuclear factor kappa-B (NF-κB) inhibitor, PLA2G12B + NF-κB inhibitor + si-PLA2R groups. Hematoxylin-eosin staining and immunofluorescence were used to detect kidney histological arrangement, serum levels of cholesterol-related indices, and AA. Genes and proteins associated with metabolism and inflammatory factors were detected by quantitative real-time PCR and Western blot. Results: The results revealed that AA metabolites were activated in the MN model mice, and the expression of PLA2G12B and NF-κB pathway levels were elevated. Besides, cellular experiments demonstrated that prostaglandin I2 (PGI2), thromboxane A2 (TXA2), leukotriene B4 (LTB4), and NF-κB pathway were significantly increased in the PLA2G12B group. Also, PLA2G12B promotes apoptosis and suppresses cell activity in podocytes, and these effects could be antagonized by NF-κB inhibitors. Furthermore, with the inference of si-PLA2R, the NF-κB inhibitors’ effects were reversed. Conclusion: Promotional effects of PLA2G12B in primary MN are associated with the regulation of AA metabolism and NF-κB pathway.

Theoretical evaluation of the malathion and its chemical derivatives interaction with cytosolic phospholipase A2 from zebrafish

Cytosolic phospholipase A2 (cPLA2) belongs to a large family of proteins and plays a crucial role in the regulation of arachidonic acid metabolism and inflammation cascade in zebrafish (Danio rerio). This enzyme with a molecular weight of 85 kDa, has two distinct domains. One is the regulatory and calcium-dependent (Ca2+) domain called C2, the other is the catalytic α/β hydrolase Ca2+-independent domain, where serine and aspartic acid catalytic dyad residues are present. We investigated the interaction of malathion and their organophosphate metabolites in the cPLA2 using in silico tools. Molecular docking results showed hydrophobic interactions with the paraoxon and catalytic site residue (Ser 223). Malathion increases intracellular Ca2+ due to endoplasmic reticulum influx which in turn activities phospholipase A2 and arachidonic acid release. Molecular docking and homology modelling of proteins and ligands could be a complementary tool for ecotoxicology and environment pollution assessment.

Gut microbiota combined with metabolomics reveal the mechanism of curcumol on liver fibrosis in mice.

Liver fibrosis is a reversible pathological process, and its prevention and treatment hold great significance for patients with chronic liver disease. This study combined 16S rRNA analysis of gut microbiota and serum metabolomics to explore the mechanism of curcumol's effect on liver fibrosis in mice. The results clarified the relationship between the gut microbiota and metabolites in the process of liver fibrosis. In this study, we randomly divided mice into a control group, a model group, and a curcumol treatment group to analyze the pathological changes in the liver tissue as well as the activities of the toll-like receptor 4 (TLR4)/nuclear factory kappa B (NF-κB) signaling pathway and inflammatory factors, such as tumor necrosis factor (TNF), interleukin 6 (IL-6), and IL-8. The gut microbiota were analyzed by 16S rRNA sequencing, and serum metabolites were examined by liquid chromatography-mass spectrometry (LC-MS) metabolomic analysis. Molecular biological testing found that curcumol could significantly improve the pathological changes of the liver tissue and inhibit the occurrence of liver inflammation. Intestinal flora testing found that curcumol could significantly change the abundances of Veillonellaceae, Prerotella_oulorum, and Alistipes_finegoldii. Metabolomics analysis found that curcumol's antihepatic fibrosis effect may be related to its regulation of arachidonic acid metabolism. Correlation analysis suggested that curcumol regulated the abundances of Bacteroidota and Bacteroides and participated in the metabolism of Prostaglandin B2. When liver fibrosis occurs, the intestinal flora and metabolic network are altered. The effect of curcumol on liver fibrosis may be related to its regulation of intestinal flora and the resulting interference with metabolic pathways, thereby reducing liver inflammation.

Glutathione peroxidase 2 is a metabolic driver of the tumor immune microenvironment and immune checkpoint inhibitor response

BackgroundThe existence of immunologically ‘cold tumors’ frequently found across a wide spectrum of tumor types represents a significant challenge for cancer immunotherapy. Cold tumors have poor baseline pan-leukocyte infiltration, including...

MiRNAs and Leukotrienes in Respiratory Syncytial Virus Infection.

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate posttranscription by binding to 3′-untranslated regions of target mRNAs. Recent functional studies have elucidated mechanisms that miRNAs regulate leukotriene synthesis by perturbing arachidonic acid metabolism. Both microarrays and high-throughput sequencing revealed distinct differential expression of miRNAs in children with respiratory syncytial virus (RSV) infection compared with healthy controls. Abnormal miRNA expression may contribute to higher leukotriene levels, which is associated with airway hyperreactivity. Targeting miRNAs may benefit to restore the homeostasis of inflammatory reaction and provide new strategies to alleviate airway hyperreactivity induced by RSV. In this article, we provide an overview of the current knowledge about miRNAs modulating leukotrienes through regulation of arachidonic acid metabolism with a special focus on miRNAs aberrantly expressed in children with RSV infection.

Testosterone replacement therapy in insulin-sensitive hypogonadal men restores phosphatidylcholine levels by regulation of arachidonic acid metabolism.

Male hypogonadism is notoriously associated with altered lipid metabolism. In this study, we performed an untargeted mass spectrometry–based profiling of plasma lipids from twenty healthy and twenty hypogonadal men before and after testosterone replacement therapy (TRT) for 60 days. Results demonstrated that hypogonadism was associated with a significant increase in sphingomyelin (SM), whereas phosphatidylcholine (PC) was mainly cleaved by activated phospholipase‐A2 into lysophosphatidylcholine (LPC). In hypogonadal patients, arachidonic acid (AA), also produced through the latter cleavage, was prevalently bio‐transformed into leukotriene B4 (LTB4) and not into endoperoxides from which prostaglandins and thromboxanes are derived. Interestingly, upon testosterone treatment SM, PC and LPC returned to levels similar to controls. Also, AA was newly converted into prostaglandin‐A2, thromboxane‐A2 and 5(S)‐hydroxyeicosatetraenoic acid (HETE), suggesting that testosterone probably plays a role in controlling hypogonadal alterations above reported.

Metabolomics combined with network pharmacology exploration reveals the modulatory properties of Astragali Radix extract in the treatment of liver fibrosis

BackgroundAstragali Radix (AR) is widely-used for improving liver fibrosis, but, the mechanism of action has not been systematically explained. This study aims to investigate the mechanism of AR intervention in liver fibrosis based on comprehensive metabolomics combined with network pharmacology approach.Materials and methodsUPLC–Q-TOF/MS based metabolomics technique was used to explore the specific metabolites and possible pathways of AR affecting the pathological process of liver fibrosis. Network pharmacology analysis was introduced to explore the key targets of AR regarding the mechanisms on liver fibrosis.ResultsAR significantly reduced the levels of ALT, AST and AKP in serum, and improved pathological characteristics. Metabolomics analysis showed that the therapeutic effect of AR was mainly related to the regulation of nine metabolites, including sphingosine, 6-keto-prostaglandin F1a, LysoPC (O-18:0), 3-dehydrosphinganine, 5,6-epoxy-8,11,14-eicosatrienoic acid, leukotriene C4, taurochenodesoxycholic acid, LysoPC (18:1 (9Z)) and 2-acetyl-1-alkyl-sn-glycero-3-phosphocholine. Pathway analysis indicated that the treatment of AR on liver fibrosis was related to arachidonic acid metabolism, ether lipid metabolism, sphingolipid metabolism, glycerophospholipid metabolism and primary bile acid biosynthesis. Validation of the key targets by network pharmacology analysis of potential metabolic markers showed that AR significantly down-regulated the expression of CYP1B1 and up-regulated the expression of CYP1A2 and PCYT1A.ConclusionMetabolomics combined with network pharmacology was used for the first time to clarify that the treatment of AR on liver fibrosis, which is related to the regulation of arachidonic acid metabolism and ether lipid metabolism by modulating the expression of CYP1A2, CYP1B1 and PCYT1A. And the integrated approach can provide new strategies and ideas for the study of molecular mechanisms of traditional Chinese medicines in the treatment of liver fibrosis.

Diversity and function of membrane glycerophospholipids generated by the remodeling pathway in mammalian cells

Cellular membranes are composed of numerous kinds of glycerophospholipids with different combinations of polar heads at the sn-3 position and acyl moieties at the sn-1 and sn-2 positions, respectively. The glycerophospholipid compositions of different cell types, organelles, and inner/outer plasma membrane leaflets are quite diverse. The acyl moieties of glycerophospholipids synthesized in the de novo pathway are subsequently remodeled by the action of phospholipases and lysophospholipid acyltransferases. This remodeling cycle contributes to the generation of membrane glycerophospholipid diversity and the production of lipid mediators such as fatty acid derivatives and lysophospholipids. Furthermore, specific glycerophospholipid transporters are also important to organize a unique glycerophospholipid composition in each organelle. Recent progress in this field contributes to understanding how and why membrane glycerophospholipid diversity is organized and maintained.

Role of long-chain acyl-coenzyme A synthetases in the regulation of arachidonic acid metabolism in interleukin 1β-stimulated rat fibroblasts

Acyl coenzyme A synthetase long-chain family members (ACSLs) are a family of enzymes that convert long-chain free fatty acids into their acyl-CoAs and play an important role in fatty acid metabolism. Here we show the role of ACSL isozymes in interleukin (IL)-1β-induced arachidonic acid (AA) metabolism in rat fibroblastic 3Y1 cells. Treatment of 3Y1 cells with triacsin C, an ACSL inhibitor, markedly enhanced the IL-1β-induced prostaglandin (PG) biosynthesis. Small interfering RNA-mediated knockdown of endogenous Acsl4 expression increased significantly the release of AA metabolites, including PGE2, PGD2, and PGF2α, compared with replicated control cells, whereas knockdown of Acsl1 expression reduced the IL-1β-induced release of AA metabolites. Experiments with double knockdown of Acsl4 and intracellular phospholipase A2 (PLA2) isozymes revealed that cytosolic PLA2α, but not calcium-independent PLA2s, is involved in the Acsl4 knockdown-enhanced PG biosynthesis. Electrospray ionization mass spectrometry of cellular phospholipids bearing AA showed that the levels of some, if not all, phosphatidylcholine (PC) and phosphatidylinositol species in Acsl4 knockdown cells were decreased after IL-1β stimulation, while those in control cells were not so obviously decreased. In Acsl1 knockdown cells, the levels of some AA-bearing PC species were reduced even in the unstimulated condition. Collectively, these results suggest that Acsl isozymes play distinct roles in the control of AA remodeling in rat fibroblasts: Acsl4 acts as the first step of enzyme for AA remodeling following IL-1β stimulation, and Acsl1 is involved in the maintenance of some AA-containing PC species.

Effect of incinerator fly ash on the regulation of arachidonic acid metabolism in macrophages

Effect of incinerator fly ash on the regulation of arachidonic acid metabolism in macrophages

Effect of incinerator fly ash on the regulation of arachidonic acid metabolism in macrophages

Effect of incinerator fly ash on the regulation of arachidonic acid metabolism in macrophages

The regulation of arachidonic acid metabolism in human first trimester trophoblast by cyclic AMP

Human trophoblast cells are known to release a range of arachidonic acid metabolites into culture medium, including cyclo-oxygenase, lipoxygenase and epoxygenase products. In this study we investigated the effects of dibutyryl cyclic AMP (db cAMP) on arachidonic acid metabolism in human first trimester trophoblast cells, and also determined the distribution of metabolites between intracellular and extracellular compartments. db cAMP increased intracellular levels of radioactivity within 2 min, and extracellular levels of radioactivity were increased after 30 min. These changes were reflected in increased levels of arachidonic acid metabolites in both compartments, indicating that arachidonic acid was metabolised. db cAMP increased intracellular levels of 5,6-epoxyeicosatrienoic acid (5,6-EpETrE) within 2 min of addition to cultured cells. No changes were detected after 5–10 min, but substantial changes were found 30 min after the addition of db cAMP. The dihydroxyeicosatrienoic acid (DiHETrE) breakdown products also increased with similar kinetics. In contrast, levels of 14,15-EpETrE increased after 5–10 min. Extracellular levels of both EpETrEs and DiHETrEs increased only after 30 min, indicating that there was a differential distribution of arachidonic acid metabolites.

Cathepsin B Mediates Tumor Necrosis Factor-induced Arachidonic Acid Release in Tumor Cells

Arachidonic acid (AA) generated by cytosolic phospholipase A2 (cPLA2) has been suggested to function as a second messenger in tumor necrosis factor (TNF)-induced death signaling. Here, we show that cathepsin B-like proteases are required for the TNF-induced AA release in transformed cells. Pharmaceutical inhibitors of cathepsin B blocked TNF-induced AA release in human breast (MCF-7S1) and cervix (ME-180as) carcinoma as well as murine fibrosarcoma (WEHI-S) cells. Furthermore, TNF-induced AA release was significantly reduced in cathepsin B-deficient immortalized murine embryonic fibroblasts. Employing cPLA2-deficient MCF-7S1 cells expressing ectopic cPLA2 or cPLA2-deficient immortalized murine embryonic fibroblasts, we showed that cPLA2 is dispensable for TNF-induced AA release and death in these cells. Furthermore, TNF-induced cathepsin B-dependent AA release could be dissociated from the cathepsin B-independent cell death in MCF-7S1 cells, whereas both events required cathepsin B activity in other cell lines tested. These data suggest that cathepsin B inhibitors may prove useful not only in the direct control of cell death but also in limiting the damage-associated inflammation.

Selenium deficiency alters the formation of eicosanoids and signal transduction in rat lymphocytes

Previous reports have shown that selenium (Se) nutrition alters the lipoxygenase pathway and mitogenic responses in bovine lymphocytes. In order to further understand how Se may alter lymphocyte function, we examined the effects of Se nutrition on arachidonic acid (AA) metabolism and phospholipase D (PLD) activation. Lymphocytes were isolated from the lymph nodes of rats fed either Se-deficient diet (−Se) or Se-supplemented diet (+Se) for 12 weeks. Our results revealed that calcium ionophore A23187-stimulated lymphocytes derived from −Se rats produced significantly less prostaglandins (PGs) than those obtained from +Se rats. Phospholipase D (PLD) activation by 12- O-tetradecanoylphorbol-13-acetate (TPA) was significantly lower in lymphocytes obtained from −Se rats when compared to cells from +Se rats. Furthermore, the addition of PGE 2, PGD 2 or PGF 2α to suspended lymphocytes from −Se rats significantly enhanced PLD activity. The effects of TPA and PGE 2 on PLD activation were additive. However, the addition of PGE 2 abolished the significant difference in PLD activation between −Se and +Se cells observed in response to TPA alone. Based on these results, we postulate that dietary Se status plays an important role in the regulation of AA metabolism that subsequently affects PLD activation.

Hormonal regulation of arachidonic acid metabolism in liver: Babenko N.A., Kavok N.S. Kharkov State University, Institute of Biology, Kharkov. 310077, Ukraine

Hormonal regulation of arachidonic acid metabolism in liver: Babenko N.A., Kavok N.S. Kharkov State University, Institute of Biology, Kharkov. 310077, Ukraine